2010年7月

# Structure of large-scale flows and their oscillation in the thermal convection of liquid gallium

PHYSICAL REVIEW E
• Takatoshi Yanagisawa
• ,
• Yasuko Yamagishi
• ,
• Yozo Hamano
• ,
• Yuji Tasaka
• ,
• Masataka Yoshida
• ,
• Kanako Yano
• ,
• Yasushi Takeda

82
1

DOI
10.1103/PhysRevE.82.016320

AMER PHYSICAL SOC

This investigation observed large-scale flows in liquid gallium and the oscillation with Rayleigh-Benard convection. An ultrasonic velocity profiling method was used to visualize the spatiotemporal flow pattern of the liquid gallium in a horizontally long rectangular vessel. Measuring the horizontal component of the flow velocity at several lines, an organized roll-like structure with four cells was observed in the 1 x 10(4)-2 x 10(5) range of Rayleigh numbers, and the rolls show clear oscillatory behavior. The long-term fluctuations in temperature observed in point measurements correspond to the oscillations of the organized roll structure. This flow structure can be interpreted as the continuous development of the oscillatory instability of two-dimensional roll convection that is theoretically investigated around the critical Rayleigh number. Both the velocity of the large-scale flows and the frequency of the oscillation increase proportional to the square root of the Rayleigh number. This indicates that the oscillation is closely related to the circulation of large-scale flow.

Web of Science ® 被引用回数 : 16

リンク情報
DOI
https://doi.org/10.1103/PhysRevE.82.016320
Web of Science